czm_material czm_getMaterial(czm_materialInput materialInput){
  czm_material material = czm_getDefaultMaterial(materialInput);

  vec3 normalWC = normalize(czm_inverseViewRotation * material.normal);
  vec3 positionWC = normalize(czm_inverseViewRotation * materialInput.positionToEyeEC);
  float cosAngIncidence = max(dot(normalWC, positionWC), 0.0);

  material.diffuse = mix(reflection.diffuse, refraction.diffuse, cosAngIncidence);

  return material;
}
